Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D319/00—Heterocyclic compounds containing six-membered rings having two oxygen atoms as the only ring hetero atoms
  • C07D319/04—1,3-Dioxanes; Hydrogenated 1,3-dioxanes
  • C07D319/06—1,3-Dioxanes; Hydrogenated 1,3-dioxanes not condensed with other rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
  • C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
  • C07C45/67—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton
  • C07C45/68—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms
  • C07C45/70—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms by reaction with functional groups containing oxygen only in singly bound form
  • C07C45/71—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms by reaction with functional groups containing oxygen only in singly bound form being hydroxy groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C47/00—Compounds having —CHO groups
  • C07C47/02—Saturated compounds having —CHO groups bound to acyclic carbon atoms or to hydrogen
  • C07C47/198—Saturated compounds having —CHO groups bound to acyclic carbon atoms or to hydrogen containing ether groups, groups, groups, or groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C47/00—Compounds having —CHO groups
  • C07C47/20—Unsaturated compounds having —CHO groups bound to acyclic carbon atoms
  • C07C47/277—Unsaturated compounds having —CHO groups bound to acyclic carbon atoms containing ether groups, groups, groups, or groups

Definitions

• the present invention relates to a process for the preparation of monoacetalized glyoxal
• the present invention relates to a process for the preparation of monoacetalized glyoxal of the general formula I: ##STR2## wherein either R 1 and R 2 , which are identical, represent a --CHRR 3 group, in which R and R 3 , which are identical or different, represent an alkyl, alkenyl or aralkyl group, or R 1 and R 2 , which are identical, represent a --CH 2 R group, in which R represents a hydrogen atom, an alkyl, alkenyl or aralkyl radical, or R 1 and R 2 together form a --CH 2 --(CRR) n --CHR--- radical, in which n represents 0 or 1 and R retains the meaning given previously.
• --CH 2 --(CRR) n --CHR-- radical examples of the --CH 2 --(CRR) n --CHR-- radical it is possible to mention the ethylene, propylene, trimethylene, 2,2-dimethyl-propane-1,3-diyl groups, etc.
• This process lies in reacting glyoxal in the presence of an acid catalyst with an excess of the corresponding alcohol of one of the general formulae (II) RR 3 CHOH, (III) RCH 2 OH or (IV) HOCH 2 --(CRR) n --CHROH, in which R, R 3 and n retain the meaning given previously, then stopping the reaction as soon as the concentration of the desired monoacetal of general formula (I) decreases in the reaction medium in favour of bisacetal.
• the Applicants have observed that, even in an aqueous solution, glyoxal reacted rapidly with the alcohols of general formula (III) or (IV) so as to give the monoacetal of general formula (I), which was then transformed less rapidly into bisacetal.
• the disappearance of glyoxal, on the one hand, and the formation of acetals, on the other hand, is followed by the analysis of samples taken regularly from the reaction medium.
• glyoxal is followed, for example, by determination of the soda required to transform it into sodium glycolate in accordance with Cannizzaro's reaction.
• the mono and bisacetals are preferably assayed by gas-phase chromatography after determination of the response coefficients using the conventional method of internal calibration.
• the process according to the invention is carried out in the presence of an acid catalyst.
• acid catalysts include hydrogen chloride, sulphuric acid, paratoluenesulphonic acid, zirconium (IV) sulphate, ion-exchange sulphonic resins in acid form. Zirconium (IV) sulphate or ion-exchange sulphonic resins in acid form are preferably used. Normallly, 50 ⁇ 25 mmoles of acid catalyst are used per mole of glyoxal introduced. At the end of the reaction, this acid catalyst is rapidly removed from the reaction medium by means known per se, for example by filtration, neutralization using a suitable base, etc.
• the reaction is carried out with excess alcohol in relation to glyoxal. This excess may vary within substantial proportions but usually 12 ⁇ 5 moles of alcohol per mole of glyoxal are used. If necessary, it is possible to operate in an inert organic solvent which is compatible with this type of acid-catalyzed nucleophilic substitution reaction, such as hexane, cyclohexane, benzene, toluene, chlorinated solvents: chloroform, dichloromethane.
• an inert organic solvent which is compatible with this type of acid-catalyzed nucleophilic substitution reaction, such as hexane, cyclohexane, benzene, toluene, chlorinated solvents: chloroform, dichloromethane.
• the starting glyoxal is either solid, such as its crystallized trimer with two molecules of water, or in aqueous solution. In this latter case, it is possible to eliminate part of the water of dissolution by prior azeotropic distillation.
• alcohols used in the process of the invention one may mention methanol, ethanol, propanol, 1-butanol, isobutyl alcohol, phenyl ethyl alcohol, allyl alcohol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, etc.
• reaction is carried out at the boiling point of the reaction medium but it can also be carried out at higher or lower temperatures.
• Normal operation takes place with azeotropic distillation of the water present and/or formed in the reaction medium with recycling of the dehydrated distillate by means known per se, such as leaching through a dessicating substance, such as anhydrous magnesium sulphate.
• the reaction is generally carried out at atmospheric pressure, although a higher or lower pressure is not detrimental to the process.
• the desired glyoxal monoacetal is isolated from the reaction medium by means known per se, such a fractional distillation or crystallization.
• the glyoxal monoacetals are very significant olefinoformylation "synthons" in organic synthesis and they are currently used to provide access, in particular, to certain heterocycles (D. Soerens et al, J. Org. Chem. 1979, 44, 535).
• the cooled reaction medium is then filtered (thereby enabling the majority of the catalyst used to be recovered), the filtrate is then treated with 10 g (12 mmoles) of dry sodium hydrogen carbonate.
• the oily residue obtained is treated with 5 volumes of diethyl oxide so as to eliminate the last traces of mineral salts.
• the residual oil is subjected to flash distillation under a vacuum of 10 mbar. 122 g of a liquid distilling at between 35° and 60° C. are thus collected, the vapour phase chromatographic analysis of which reveals the presence of about 70% of 2,2-diethoxy ethanal and 30% of 1,1,2,2-tetraethoxy ethane.
• a second distillation carried out on a distillation apparatus with a rotating-belt column makes it possible to isolate 80 g (0.61 mole) of 2,2-diethoxy ethanal distilling at 43 ⁇ 2° C. at 11 mbar.
• vapour phase chromatographic analysis of a sample of the reaction medium reveals the presence of 0.1 mole of unconverted glyoxal, 0.85 mole of 2,2-dibutoxy ethanal and 0.05 mole of 1,1,2,2-tetrabutoxy ethane.
• Resin A macroporous resin sold under the name IMAC C 16 P (cf. Encyclopedia of Chemical Technology, Kirk-Othmer, 3rd edition, 13, 696).
• Resin B NAFION resin (cf. Encyclopedia of Chemical Technology, Kirk-Othmer, 3rd edition S 559).
• Example 2 113 g (0.6 mole) of 2,2-diisobutoxy ethanal are thus isolated, distilling at 52° C. at 6 mbar and 95 g (0.3 mole) of 1,1,2,2-tetraisobutoxy ethane distilling at 94°-99° C. at 5 mbar.
• the reaction medium is then treated as in Example 2.
• 2,2-diisopropoxy ethanal is a colourless, very fluid liquid which is soluble in water and the usual organic solvents.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Catalysts (AREA)

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Citations (3)

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• 1987
  • 1987-06-01 US US07/061,015 patent/US4835320A/en not_active Expired - Lifetime
  • 1987-06-02 DE DE8787401227T patent/DE3764544D1/de not_active Expired - Lifetime
  • 1987-06-02 ES ES87401227T patent/ES2017506B3/es not_active Expired - Lifetime
  • 1987-06-02 DE DE8989122806T patent/DE3782664T2/de not_active Expired - Fee Related
  • 1987-06-02 JP JP62138848A patent/JP2515548B2/ja not_active Expired - Lifetime
  • 1987-06-02 EP EP87401227A patent/EP0249530B1/fr not_active Expired - Lifetime
  • 1987-06-02 EP EP89122806A patent/EP0368363B1/fr not_active Expired - Lifetime
  • 1987-06-03 CA CA000538740A patent/CA1268773A/fr not_active Expired
• 1990
  • 1990-11-06 GR GR90400872T patent/GR3001053T3/el unknown
• 1992
  • 1992-11-19 GR GR920402645T patent/GR3006286T3/el unknown

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